Lock



FIG. 1 is a front perspective view of a lock showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a right side view thereof; and,

FIG. 7 is a left side view thereof.

The portions of the Figures shown in broken lines are not part of the claimed design and are for illustration only.

The broken lines, which define the bounds of the claimed design, form no part thereof. 

I claim the ornamental design for a lock, as shown and described. 